They should pip the wide end of the egg. Sometimes, they can pip the pointy end and be just fine. Mine were not, sadly. The "normal" place to pip is along the side of the wide part of the egg. Every now and then you get one that pips the end, and then zips from there. How long has it been since they pipped? If you open the incubator, you risk shrinkwrapping the membrane to them and they can't get out of the shell. It seemed like this happened to me, even though my humidity was still up high after getting the bleeding chick out, the drop was enough to shrinkwrap the other that had pipped, which I then had to help as well. Sometimes pip to zip can take more than 24 hours. In my experience, it seems to happen more quickly...usually 4-8 hours.